src/kitemviews/kitemlistview.h

   1 /*
   2  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
   3  *
   4  * Based on the Itemviews NG project from Trolltech Labs
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #ifndef KITEMLISTVIEW_H
  10 #define KITEMLISTVIEW_H
  11
  12 #include <optional>
  13
  14 #include "dolphin_export.h"
  15 #include "kitemviews/kitemliststyleoption.h"
  16 #include "kitemviews/kitemlistwidget.h"
  17 #include "kitemviews/kitemmodelbase.h"
  18 #include "kitemviews/kstandarditemlistgroupheader.h"
  19 #include "kitemviews/private/kitemlistviewanimation.h"
  20
  21 #include <QGraphicsWidget>
  22 #include <QSet>
  23
  24 class KItemListContainer;
  25 class KItemListContainerAccessible;
  26 class KItemListController;
  27 class KItemListGroupHeaderCreatorBase;
  28 class KItemListHeader;
  29 class KItemListHeaderWidget;
  30 class KItemListSizeHintResolver;
  31 class KItemListRubberBand;
  32 class KItemListViewAnimation;
  33 class KItemListViewLayouter;
  34 class KItemListWidget;
  35 class KItemListWidgetInformant;
  36 class KItemListWidgetCreatorBase;
  37 class QTimer;
  38 class QPropertyAnimation;
  39 class QVariantAnimation;
  40
  41 /**
  42  * @brief Represents the view of an item-list.
  43  *
  44  * The view is responsible for showing the items of the model within
  45  * a GraphicsItem. Each visible item is represented by a KItemListWidget.
  46  *
  47  * The created view must be applied to the KItemListController with
  48  * KItemListController::setView() or with the constructor of
  49  * KItemListController.
  50  *
  51  * @see KItemListWidget
  52  * @see KItemModelBase
  53  */
  54 class DOLPHIN_EXPORT KItemListView : public QGraphicsWidget
  55 {
  56     Q_OBJECT
  57
  58     Q_PROPERTY(qreal scrollOffset READ scrollOffset WRITE setScrollOffset NOTIFY scrollOffsetChanged)
  59     Q_PROPERTY(qreal itemOffset READ itemOffset WRITE setItemOffset NOTIFY itemOffsetChanged)
  60
  61 public:
  62     /** The position in the view to which an item should be scrolled to. */
  63     enum ViewItemPosition { Beginning, Middle, End, Nearest };
  64
  65     explicit KItemListView(QGraphicsWidget *parent = nullptr);
  66     ~KItemListView() override;
  67
  68     /**
  69      * Offset of the scrollbar that represents the scroll-orientation
  70      * (see setScrollOrientation()).
  71      */
  72     void setScrollOffset(qreal offset);
  73     qreal scrollOffset() const;
  74
  75     qreal maximumScrollOffset() const;
  76
  77     /**
  78      * Offset related to an item, that does not fit into the available
  79      * size of the listview. If the scroll-orientation is vertical
  80      * the item-offset describes the offset of the horizontal axe, if
  81      * the scroll-orientation is horizontal the item-offset describes
  82      * the offset of the vertical axe.
  83      */
  84     void setItemOffset(qreal scrollOffset);
  85     qreal itemOffset() const;
  86
  87     qreal maximumItemOffset() const;
  88
  89     int maximumVisibleItems() const;
  90
  91     void setVisibleRoles(const QList<QByteArray> &roles);
  92     QList<QByteArray> visibleRoles() const;
  93
  94     /**
  95      * If set to true an automatic scrolling is done as soon as the
  96      * mouse is moved near the borders of the view. Per default
  97      * the automatic scrolling is turned off.
  98      */
  99     void setAutoScroll(bool enabled);
 100     bool autoScroll() const;
 101
 102     /**
 103      * If set to true selection-toggles will be shown when hovering
 104      * an item. Per default the selection-toggles are disabled.
 105      */
 106     void setEnabledSelectionToggles(bool enabled);
 107     bool enabledSelectionToggles() const;
 108
 109     /**
 110      * @return Controller of the item-list. The controller gets
 111      *         initialized by KItemListController::setView() and will
 112      *         result in calling KItemListController::onControllerChanged().
 113      */
 114     KItemListController *controller() const;
 115
 116     /**
 117      * @return Model of the item-list. The model gets
 118      *         initialized by KItemListController::setModel() and will
 119      *         result in calling KItemListController::onModelChanged().
 120      */
 121     KItemModelBase *model() const;
 122
 123     /**
 124      * Sets the creator that creates a widget showing the
 125      * content of one model-item. Usually it is sufficient
 126      * to implement a custom widget X derived from KItemListWidget and
 127      * set the creator by:
 128      * <code>
 129      * itemListView->setWidgetCreator(new KItemListWidgetCreator<X>());
 130      * </code>
 131      * The ownership of the widget creator is transferred to
 132      * the item-list view.
 133      **/
 134     void setWidgetCreator(KItemListWidgetCreatorBase *widgetCreator);
 135     KItemListWidgetCreatorBase *widgetCreator() const;
 136
 137     /**
 138      * Sets the creator that creates a group header. Usually it is sufficient
 139      * to implement a custom header widget X derived from KItemListGroupHeader and
 140      * set the creator by:
 141      * <code>
 142      * itemListView->setGroupHeaderCreator(new KItemListGroupHeaderCreator<X>());
 143      * </code>
 144      * The ownership of the gropup header creator is transferred to
 145      * the item-list view.
 146      **/
 147     void setGroupHeaderCreator(KItemListGroupHeaderCreatorBase *groupHeaderCreator);
 148     KItemListGroupHeaderCreatorBase *groupHeaderCreator() const;
 149
 150 #ifndef QT_NO_ACCESSIBILITY
 151     /**
 152      * Uses \a parent to create an accessible object for \a parent. That accessible object will
 153      * then be used as the accessible parent of the accessible object for this KItemListView.
 154      * Make sure \a parent is the container which contains this specific KItemListView.
 155      * This method must be called once before the accessible interface is queried for this class.
 156      */
 157     void setAccessibleParentsObject(KItemListContainer *accessibleParentsObject);
 158     /** The parent of the QAccessibilityInterface of this class. */
 159     KItemListContainerAccessible *accessibleParent();
 160 #endif
 161
 162     /**
 163      * @return The basic size of all items. The size of an item may be larger than
 164      *         the basic size (see KItemListView::itemRect()).
 165      */
 166     QSizeF itemSize() const;
 167
 168     const KItemListStyleOption &styleOption() const;
 169
 170     void setGeometry(const QRectF &rect) override;
 171
 172     /**
 173      * @return The page step which should be used by the vertical scroll bar.
 174      *         This is the height of the view except for the header widget.
 175      */
 176     qreal verticalPageStep() const;
 177
 178     /**
 179      * @return Index of the item that is below the point \a pos.
 180      *         The position is relative to the upper right of
 181      *         the visible area. Only (at least partly) visible
 182      *         items are considered. std::nullopt is returned if
 183      *         no item is below the position.
 184      */
 185     std::optional<int> itemAt(const QPointF &pos) const;
 186     bool isAboveSelectionToggle(int index, const QPointF &pos) const;
 187     bool isAboveExpansionToggle(int index, const QPointF &pos) const;
 188     bool isAboveText(int index, const QPointF &pos) const;
 189
 190     /**
 191      * @return Index of the first item that is at least partly visible.
 192      *         -1 is returned if the model contains no items.
 193      */
 194     int firstVisibleIndex() const;
 195
 196     /**
 197      * @return Index of the last item that is at least partly visible.
 198      *         -1 is returned if the model contains no items.
 199      */
 200     int lastVisibleIndex() const;
 201
 202     /**
 203      * Calculates the required size for all items in the model.
 204      * It might be larger than KItemListView::itemSize().
 205      * In this case the layout grid will be stretched to assure an
 206      * unclipped item.
 207      *
 208      * @note the logical height (width) is actually the
 209      * width (height) if the scroll orientation is Qt::Vertical!
 210      */
 211     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint) const;
 212
 213     /**
 214      * If set to true, items having child-items can be expanded to show the child-items as
 215      * part of the view. Per default the expanding of items is disabled. If expanding of
 216      * items is enabled, the methods KItemModelBase::setExpanded(), KItemModelBase::isExpanded(),
 217      * KItemModelBase::isExpandable() and KItemModelBase::expandedParentsCount()
 218      * must be reimplemented. The view-implementation
 219      * has to take care itself how to visually represent the expanded items provided
 220      * by the model.
 221      */
 222     void setSupportsItemExpanding(bool supportsExpanding);
 223     bool supportsItemExpanding() const;
 224
 225     void setHighlightEntireRow(bool highlightEntireRow);
 226     bool highlightEntireRow() const;
 227
 228     void setAlternateBackgrounds(bool alternate);
 229     bool alternateBackgrounds() const;
 230
 231     /**
 232      * @return The rectangle of the item relative to the top/left of
 233      *         the currently visible area (see KItemListView::offset()).
 234      */
 235     QRectF itemRect(int index) const;
 236
 237     /**
 238      * @return The context rectangle of the item relative to the top/left of
 239      *         the currently visible area (see KItemListView::offset()). The
 240      *         context rectangle is defined by the united rectangle of
 241      *         the icon rectangle and the text rectangle (see KItemListWidget::iconRect()
 242      *         and KItemListWidget::textRect()) and is useful as reference for e.g. aligning
 243      *         a tooltip or a context-menu for an item. Note that a context rectangle will
 244      *         only be returned for (at least partly) visible items. An empty rectangle will
 245      *         be returned for fully invisible items.
 246      */
 247     QRectF itemContextRect(int index) const;
 248
 249     /**
 250      * @return Whether or not the name of the file has been elided. At present this will
 251      *         only ever be true when in icons view.
 252      */
 253     bool isElided(int index) const;
 254
 255     /**
 256      * Scrolls to the item with the index \a index so that the item
 257      * will be fully visible. The item is positioned within the view
 258      * as specified by \a viewItemPosition.
 259      */
 260     void scrollToItem(int index, ViewItemPosition viewItemPosition = ViewItemPosition::Nearest);
 261
 262     /**
 263      * If several properties of KItemListView are changed synchronously, it is
 264      * recommended to encapsulate the calls between beginTransaction() and endTransaction().
 265      * This prevents unnecessary and expensive layout-calculations.
 266      */
 267     void beginTransaction();
 268
 269     /**
 270      * Counterpart to beginTransaction(). The layout changes will only be animated if
 271      * all property changes between beginTransaction() and endTransaction() support
 272      * animations.
 273      */
 274     void endTransaction();
 275
 276     bool isTransactionActive() const;
 277
 278     /**
 279      * Turns on the header if \p visible is true. Per default the
 280      * header is not visible. Usually the header is turned on when
 281      * showing a classic "table-view" to describe the shown columns.
 282      */
 283     void setHeaderVisible(bool visible);
 284     bool isHeaderVisible() const;
 285
 286     /**
 287      * @return Header of the list. The header is also available if it is not shown
 288      *         (see KItemListView::setHeaderShown()).
 289      */
 290     KItemListHeader *header() const;
 291
 292     /**
 293      * @return Pixmap that is used for a drag operation based on the
 294      *         items given by \a indexes.
 295      */
 296     virtual QPixmap createDragPixmap(const KItemSet &indexes) const;
 297
 298     /**
 299      * Lets the user edit the role \a role for item with the index \a index.
 300      */
 301     void editRole(int index, const QByteArray &role);
 302
 303     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 304
 305     /**
 306      * Set the bottom offset for moving the view so that the small overlayed statusbar
 307      * won't cover any items by accident.
 308      */
 309     void setStatusBarOffset(int offset);
 310
 311 Q_SIGNALS:
 312     void scrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 313     void scrollOffsetChanged(qreal current, qreal previous);
 314     void maximumScrollOffsetChanged(qreal current, qreal previous);
 315     void itemOffsetChanged(qreal current, qreal previous);
 316     void maximumItemOffsetChanged(qreal current, qreal previous);
 317     void scrollTo(qreal newOffset);
 318
 319     /**
 320      * Is emitted if the user has changed the sort order by clicking on a
 321      * header item (see KItemListView::setHeaderShown()). The sort order
 322      * of the model has already been adjusted to
 323      * the current sort order. Note that no signal will be emitted if the
 324      * sort order of the model has been changed without user interaction.
 325      */
 326     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 327
 328     /**
 329      * Is emitted if the user has changed the sort role by clicking on a
 330      * header item (see KItemListView::setHeaderShown()). The sort role
 331      * of the model has already been adjusted to
 332      * the current sort role. Note that no signal will be emitted if the
 333      * sort role of the model has been changed without user interaction.
 334      */
 335     void sortRoleChanged(const QByteArray &current, const QByteArray &previous);
 336
 337     /**
 338      * Is emitted if the user has changed the visible roles by moving a header
 339      * item (see KItemListView::setHeaderShown()). Note that no signal will be
 340      * emitted if the roles have been changed without user interaction by
 341      * KItemListView::setVisibleRoles().
 342      */
 343     void visibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 344
 345     void roleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 346     void roleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 347
 348     /**
 349      * Emitted once scrolling has finished, or immediately if no scrolling was necessary
 350      * to get item in view in scrollToItem.
 351      */
 352     void scrollingStopped();
 353
 354     void columnHovered(int roleIndex);
 355     void columnUnHovered(int roleIndex);
 356
 357 protected:
 358     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;
 359     void setItemSize(const QSizeF &size);
 360     void setStyleOption(const KItemListStyleOption &option);
 361
 362     /**
 363      * If the scroll-orientation is vertical, the items are ordered
 364      * from top to bottom (= default setting). If the scroll-orientation
 365      * is horizontal, the items are ordered from left to right.
 366      */
 367     void setScrollOrientation(Qt::Orientation orientation);
 368     Qt::Orientation scrollOrientation() const;
 369
 370     /**
 371      * Factory method for creating a default widget-creator. The method will be used
 372      * in case if setWidgetCreator() has not been set by the application.
 373      * @return New instance of the widget-creator that should be used per
 374      *         default.
 375      */
 376     virtual KItemListWidgetCreatorBase *defaultWidgetCreator() const;
 377
 378     /**
 379      * Factory method for creating a default group-header-creator. The method will be used
 380      * in case if setGroupHeaderCreator() has not been set by the application.
 381      * @return New instance of the group-header-creator that should be used per
 382      *         default.
 383      */
 384     virtual KItemListGroupHeaderCreatorBase *defaultGroupHeaderCreator() const;
 385
 386     /**
 387      * Is called when creating a new KItemListWidget instance and allows derived
 388      * classes to do a custom initialization.
 389      */
 390     virtual void initializeItemListWidget(KItemListWidget *item);
 391
 392     /**
 393      * @return True if at least one of the changed roles \p changedRoles might result
 394      *         in the need to update the item-size hint (see KItemListView::itemSizeHint()).
 395      *         Per default true is returned which means on each role-change of existing items
 396      *         the item-size hints are recalculated. For performance reasons it is recommended
 397      *         to return false in case if a role-change will not result in a changed
 398      *         item-size hint.
 399      */
 400     virtual bool itemSizeHintUpdateRequired(const QSet<QByteArray> &changedRoles) const;
 401
 402     virtual void onControllerChanged(KItemListController *current, KItemListController *previous);
 403     virtual void onModelChanged(KItemModelBase *current, KItemModelBase *previous);
 404
 405     virtual void onScrollOrientationChanged(Qt::Orientation current, Qt::Orientation previous);
 406     virtual void onItemSizeChanged(const QSizeF &current, const QSizeF &previous);
 407     virtual void onScrollOffsetChanged(qreal current, qreal previous);
 408     virtual void onVisibleRolesChanged(const QList<QByteArray> &current, const QList<QByteArray> &previous);
 409     virtual void onStyleOptionChanged(const KItemListStyleOption &current, const KItemListStyleOption &previous);
 410     virtual void onHighlightEntireRowChanged(bool highlightEntireRow);
 411     virtual void onSupportsItemExpandingChanged(bool supportsExpanding);
 412
 413     virtual void onTransactionBegin();
 414     virtual void onTransactionEnd();
 415
 416     bool event(QEvent *event) override;
 417     void mousePressEvent(QGraphicsSceneMouseEvent *event) override;
 418     void mouseMoveEvent(QGraphicsSceneMouseEvent *event) override;
 419     void dragEnterEvent(QGraphicsSceneDragDropEvent *event) override;
 420     void dragMoveEvent(QGraphicsSceneDragDropEvent *event) override;
 421     void dragLeaveEvent(QGraphicsSceneDragDropEvent *event) override;
 422     void dropEvent(QGraphicsSceneDragDropEvent *event) override;
 423
 424     QList<KItemListWidget *> visibleItemListWidgets() const;
 425
 426     virtual void updateFont();
 427     virtual void updatePalette();
 428
 429 protected Q_SLOTS:
 430     virtual void slotItemsInserted(const KItemRangeList &itemRanges);
 431     virtual void slotItemsRemoved(const KItemRangeList &itemRanges);
 432     virtual void slotItemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes);
 433     virtual void slotItemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles);
 434     virtual void slotGroupsChanged();
 435
 436     virtual void slotGroupedSortingChanged(bool current);
 437     virtual void slotSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 438     virtual void slotSortRoleChanged(const QByteArray &current, const QByteArray &previous);
 439     virtual void slotCurrentChanged(int current, int previous);
 440     virtual void slotSelectionChanged(const KItemSet &current, const KItemSet &previous);
 441
 442 private Q_SLOTS:
 443     void slotAnimationFinished(QGraphicsWidget *widget, KItemListViewAnimation::AnimationType type);
 444
 445     void slotRubberBandPosChanged();
 446     void slotRubberBandActivationChanged(bool active);
 447
 448     /**
 449      * Is invoked if the column-width of one role in the header has
 450      * been changed by the user. The automatic resizing of columns
 451      * will be turned off as soon as this method has been called at
 452      * least once.
 453      */
 454     void slotHeaderColumnWidthChanged(const QByteArray &role, qreal currentWidth, qreal previousWidth);
 455
 456     void slotSidePaddingChanged(qreal width);
 457
 458     /**
 459      * Is invoked if a column has been moved by the user. Applies
 460      * the moved role to the view.
 461      */
 462     void slotHeaderColumnMoved(const QByteArray &role, int currentIndex, int previousIndex);
 463
 464     /**
 465      * Triggers the autoscrolling if autoScroll() is enabled by checking the
 466      * current mouse position. If the mouse position is within the autoscroll
 467      * margins a timer will be started that periodically triggers the autoscrolling.
 468      */
 469     void triggerAutoScrolling();
 470
 471     /**
 472      * Is invoked if the geometry of the parent-widget from a group-header has been
 473      * changed. The x-position and width of the group-header gets adjusted to assure
 474      * that it always spans the whole width even during temporary transitions of the
 475      * parent widget.
 476      */
 477     void slotGeometryOfGroupHeaderParentChanged();
 478
 479     void slotRoleEditingCanceled(int index, const QByteArray &role, const QVariant &value);
 480     void slotRoleEditingFinished(int index, const QByteArray &role, const QVariant &value);
 481
 482 private:
 483     enum LayoutAnimationHint { NoAnimation, Animation };
 484
 485     enum SizeType { LayouterSize, ItemSize };
 486
 487     void setController(KItemListController *controller);
 488     void setModel(KItemModelBase *model);
 489
 490     KItemListRubberBand *rubberBand() const;
 491
 492     void doLayout(LayoutAnimationHint hint, int changedIndex = 0, int changedCount = 0);
 493
 494     /**
 495      * Helper method for doLayout: Returns a list of items that can be reused for the visible
 496      * area. Invisible group headers get recycled. The reusable items are items that are
 497      * invisible. If the animation hint is 'Animation' then items that are currently animated
 498      * won't be reused. Reusing items is faster in comparison to deleting invisible
 499      * items and creating a new instance for visible items.
 500      */
 501     QList<int> recycleInvisibleItems(int firstVisibleIndex, int lastVisibleIndex, LayoutAnimationHint hint);
 502
 503     /**
 504      * Helper method for doLayout: Starts a moving-animation for the widget to the given
 505      * new position. The moving-animation is only started if the new position is within
 506      * the same row or column, otherwise the create-animation is used instead.
 507      * @return True if the moving-animation has been applied.
 508      */
 509     bool moveWidget(KItemListWidget *widget, const QPointF &newPos);
 510
 511     void emitOffsetChanges();
 512
 513     KItemListWidget *createWidget(int index);
 514     void recycleWidget(KItemListWidget *widget);
 515
 516     /**
 517      * Changes the index of the widget to \a index and assures a consistent
 518      * update for m_visibleItems and m_visibleCells. The cell-information
 519      * for the new index will not be updated and be initialized as empty cell.
 520      */
 521     void setWidgetIndex(KItemListWidget *widget, int index);
 522
 523     /**
 524      * Changes the index of the widget to \a index. In opposite to
 525      * setWidgetIndex() the cell-information for the widget gets updated.
 526      * This update gives doLayout() the chance to animate the moving
 527      * of the item visually (see moveWidget()).
 528      */
 529     void moveWidgetToIndex(KItemListWidget *widget, int index);
 530
 531     /**
 532      * Helper method for prepareLayoutForIncreasedItemCount().
 533      */
 534     void setLayouterSize(const QSizeF &size, SizeType sizeType);
 535
 536     /**
 537      * Helper method for createWidget() and setWidgetIndex() to update the properties
 538      * of the itemlist widget.
 539      */
 540     void updateWidgetProperties(KItemListWidget *widget, int index);
 541
 542     /**
 543      * Helper method for updateWidgetPropertes() to create or update
 544      * the itemlist group-header.
 545      */
 546     void updateGroupHeaderForWidget(KItemListWidget *widget);
 547
 548     /**
 549      * Updates the position and size of the group-header that belongs
 550      * to the itemlist widget \a widget. The given widget must represent
 551      * the first item of a group.
 552      */
 553     void updateGroupHeaderLayout(KItemListWidget *widget);
 554
 555     /**
 556      * Recycles the group-header for the widget.
 557      */
 558     void recycleGroupHeaderForWidget(KItemListWidget *widget);
 559
 560     /**
 561      * Helper method for slotGroupedSortingChanged(), slotSortOrderChanged()
 562      * and slotSortRoleChanged(): Iterates through all visible items and updates
 563      * the group-header widgets.
 564      */
 565     void updateVisibleGroupHeaders();
 566
 567     /**
 568      * @return Index for the item in the list returned by KItemModelBase::groups()
 569      *         that represents the group where the item with the index \a index
 570      *         belongs to. -1 is returned if no groups are available.
 571      */
 572     int groupIndexForItem(int index) const;
 573
 574     /**
 575      * Updates the alternate background for all visible items.
 576      * @see updateAlternateBackgroundForWidget()
 577      */
 578     void updateAlternateBackgrounds();
 579
 580     /**
 581      * Updates the alternateBackground-property of the widget dependent
 582      * on the state of useAlternateBackgrounds() and the grouping state.
 583      */
 584     void updateAlternateBackgroundForWidget(KItemListWidget *widget);
 585
 586     /**
 587      * @return True if alternate backgrounds should be used for the items.
 588      *         This is the case if an empty item-size is given and if there
 589      *         is more than one visible role.
 590      */
 591     bool useAlternateBackgrounds() const;
 592
 593     /**
 594      * @param itemRanges Items that must be checked for getting the widths of columns.
 595      * @return           The preferred width of the column of each visible role. The width will
 596      *                   be respected if the width of the item size is <= 0 (see
 597      *                   KItemListView::setItemSize()). Per default an empty hash
 598      *                   is returned.
 599      */
 600     QHash<QByteArray, qreal> preferredColumnWidths(const KItemRangeList &itemRanges) const;
 601
 602     /**
 603      * Applies the column-widths from m_headerWidget to the layout
 604      * of the view.
 605      */
 606     void applyColumnWidthsFromHeader();
 607
 608     /**
 609      * Applies the column-widths from m_headerWidget to \a widget.
 610      */
 611     void updateWidgetColumnWidths(KItemListWidget *widget);
 612
 613     /**
 614      * Updates the preferred column-widths of m_groupHeaderWidget by
 615      * invoking KItemListView::columnWidths().
 616      */
 617     void updatePreferredColumnWidths(const KItemRangeList &itemRanges);
 618
 619     /**
 620      * Convenience method for
 621      * updatePreferredColumnWidths(KItemRangeList() << KItemRange(0, m_model->count()).
 622      */
 623     void updatePreferredColumnWidths();
 624
 625     /**
 626      * Resizes the column-widths of m_headerWidget based on the preferred widths
 627      * and the available view-size.
 628      */
 629     void applyAutomaticColumnWidths();
 630
 631     /**
 632      * @return Sum of the widths of all columns.
 633      */
 634     qreal columnWidthsSum() const;
 635
 636     /**
 637      * @return Boundaries of the header. An empty rectangle is returned
 638      *         if no header is shown.
 639      */
 640     QRectF headerBoundaries() const;
 641
 642     /**
 643      * @return True if the number of columns or rows will be changed when applying
 644      *         the new grid- and item-size. Used to determine whether an animation
 645      *         should be done when applying the new layout.
 646      */
 647     bool changesItemGridLayout(const QSizeF &newGridSize, const QSizeF &newItemSize, const QSizeF &newItemMargin) const;
 648
 649     /**
 650      * @param changedItemCount Number of inserted  or removed items.
 651      * @return                 True if the inserting or removing of items should be animated.
 652      *                         No animation should be done if the number of items is too large
 653      *                         to provide a pleasant animation.
 654      */
 655     bool animateChangedItemCount(int changedItemCount) const;
 656
 657     /**
 658      * @return True if a scrollbar for the given scroll-orientation is required
 659      *         when using a size of \p size for the view. Calling the method is rather
 660      *         expansive as a temporary relayout needs to be done.
 661      */
 662     bool scrollBarRequired(const QSizeF &size) const;
 663
 664     /**
 665      * Shows a drop-indicator between items dependent on the given
 666      * cursor position. The cursor position is relative to the upper left
 667      * edge of the view.
 668      * @return Index of the item where the dropping is done. An index of -1
 669      *         indicates that the item has been dropped after the last item.
 670      */
 671     int showDropIndicator(const QPointF &pos);
 672     void hideDropIndicator();
 673
 674     /**
 675      * Applies the height of the group header to the layouter. The height
 676      * depends on the used scroll orientation.
 677      */
 678     void updateGroupHeaderHeight();
 679
 680     /**
 681      * Updates the siblings-information for all visible items that are inside
 682      * the range of \p firstIndex and \p lastIndex. If firstIndex or lastIndex
 683      * is smaller than 0, the siblings-information for all visible items gets
 684      * updated.
 685      * @see KItemListWidget::setSiblingsInformation()
 686      */
 687     void updateSiblingsInformation(int firstIndex = -1, int lastIndex = -1);
 688
 689     /**
 690      * Helper method for updateExpansionIndicators().
 691      * @return True if the item with the index \a index has a sibling successor
 692      *         (= the item is not the last item of the current hierarchy).
 693      */
 694     bool hasSiblingSuccessor(int index) const;
 695
 696     /**
 697      * Helper method for slotRoleEditingCanceled() and slotRoleEditingFinished().
 698      * Disconnects the two Signals "roleEditingCanceled" and
 699      * "roleEditingFinished"
 700      */
 701     void disconnectRoleEditingSignals(int index);
 702
 703     /**
 704      * Helper function for triggerAutoScrolling().
 705      * @param pos    Logical position of the mouse relative to the range.
 706      * @param range  Range of the visible area.
 707      * @param oldInc Previous increment. Is used to assure that the increment
 708      *               increases only gradually.
 709      * @return Scroll increment that should be added to the offset().
 710      *         As soon as \a pos is inside the autoscroll-margin a
 711      *         value != 0 will be returned.
 712      */
 713     static int calculateAutoScrollingIncrement(int pos, int range, int oldInc);
 714
 715     /**
 716      * Helper functions for changesItemCount().
 717      * @return The number of items that fit into the available size by
 718      *         respecting the size of the item and the margin between the items.
 719      */
 720     static int itemsPerSize(qreal size, qreal itemSize, qreal itemMargin);
 721
 722 private:
 723     bool m_enabledSelectionToggles;
 724     bool m_grouped;
 725     bool m_highlightEntireRow;
 726     bool m_alternateBackgrounds;
 727     bool m_supportsItemExpanding;
 728     bool m_editingRole;
 729     int m_activeTransactions; // Counter for beginTransaction()/endTransaction()
 730     LayoutAnimationHint m_endTransactionAnimationHint;
 731
 732     QSizeF m_itemSize;
 733     KItemListController *m_controller;
 734     KItemModelBase *m_model;
 735     QList<QByteArray> m_visibleRoles;
 736     mutable KItemListWidgetCreatorBase *m_widgetCreator;
 737     mutable KItemListGroupHeaderCreatorBase *m_groupHeaderCreator;
 738 #ifndef QT_NO_ACCESSIBILITY
 739     /** The object that will be the parent of this classes QAccessibleInterface. */
 740     KItemListContainerAccessible *m_accessibleParent = nullptr;
 741 #endif
 742     KItemListStyleOption m_styleOption;
 743
 744     QHash<int, KItemListWidget *> m_visibleItems;
 745     QHash<KItemListWidget *, KItemListGroupHeader *> m_visibleGroups;
 746
 747     struct Cell {
 748         Cell()
 749             : column(-1)
 750             , row(-1)
 751         {
 752         }
 753         Cell(int c, int r)
 754             : column(c)
 755             , row(r)
 756         {
 757         }
 758         int column;
 759         int row;
 760     };
 761     QHash<int, Cell> m_visibleCells;
 762
 763     int m_scrollBarExtent;
 764     KItemListViewLayouter *m_layouter;
 765     KItemListViewAnimation *m_animation;
 766
 767     qreal m_oldScrollOffset;
 768     qreal m_oldMaximumScrollOffset;
 769     qreal m_oldItemOffset;
 770     qreal m_oldMaximumItemOffset;
 771
 772     bool m_skipAutoScrollForRubberBand;
 773     KItemListRubberBand *m_rubberBand;
 774     KItemListRubberBand *m_tapAndHoldIndicator;
 775
 776     QPointF m_mousePos;
 777     int m_autoScrollIncrement;
 778     QTimer *m_autoScrollTimer;
 779
 780     KItemListHeader *m_header;
 781     KItemListHeaderWidget *m_headerWidget;
 782
 783     QPropertyAnimation *m_indicatorAnimation;
 784
 785     int m_statusBarOffset;
 786
 787     // When dragging items into the view where the sort-role of the model
 788     // is empty, a visual indicator should be shown during dragging where
 789     // the dropping will happen. This indicator is specified by an index
 790     // of the item. -1 means that no indicator will be shown at all.
 791     // The m_dropIndicator is set by the KItemListController
 792     // by KItemListView::showDropIndicator() and KItemListView::hideDropIndicator().
 793     QRectF m_dropIndicator;
 794
 795     QList<QVariantAnimation *> m_rubberBandAnimations;
 796
 797     KItemListSizeHintResolver *m_sizeHintResolver;
 798
 799     friend class KItemListContainer; // Accesses scrollBarRequired()
 800     friend class KItemListHeader; // Accesses m_headerWidget
 801     friend class KItemListController;
 802     friend class KItemListControllerTest;
 803     friend class KItemListViewAccessible;
 804     friend class KItemListDelegateAccessible;
 805
 806     friend class DolphinMainWindowTest;
 807 };
 808
 809 /**
 810  * Allows to do a fast logical creation and deletion of QGraphicsWidgets
 811  * by recycling existing QGraphicsWidgets instances. Is used by
 812  * KItemListWidgetCreatorBase and KItemListGroupHeaderCreatorBase.
 813  * @internal
 814  */
 815 class DOLPHIN_EXPORT KItemListCreatorBase
 816 {
 817 public:
 818     virtual ~KItemListCreatorBase();
 819
 820 protected:
 821     void addCreatedWidget(QGraphicsWidget *widget);
 822     void pushRecycleableWidget(QGraphicsWidget *widget);
 823     QGraphicsWidget *popRecycleableWidget();
 824
 825 private:
 826     QSet<QGraphicsWidget *> m_createdWidgets;
 827     QList<QGraphicsWidget *> m_recycleableWidgets;
 828 };
 829
 830 /**
 831  * @brief Base class for creating KItemListWidgets.
 832  *
 833  * It is recommended that applications simply use the KItemListWidgetCreator-template class.
 834  * For a custom implementation the methods create(), itemSizeHint() and preferredColumnWith()
 835  * must be reimplemented. The intention of the widget creator is to prevent repetitive and
 836  * expensive instantiations and deletions of KItemListWidgets by recycling existing widget
 837  * instances.
 838  */
 839 class DOLPHIN_EXPORT KItemListWidgetCreatorBase : public KItemListCreatorBase
 840 {
 841 public:
 842     ~KItemListWidgetCreatorBase() override;
 843
 844     virtual KItemListWidget *create(KItemListView *view) = 0;
 845
 846     virtual void recycle(KItemListWidget *widget);
 847
 848     virtual void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const = 0;
 849
 850     virtual qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const = 0;
 851 };
 852
 853 /**
 854  * @brief Template class for creating KItemListWidgets.
 855  */
 856 template<class T>
 857 class KItemListWidgetCreator : public KItemListWidgetCreatorBase
 858 {
 859 public:
 860     KItemListWidgetCreator();
 861     ~KItemListWidgetCreator() override;
 862
 863     KItemListWidget *create(KItemListView *view) override;
 864
 865     void calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints, qreal &logicalWidthHint, const KItemListView *view) const override;
 866
 867     qreal preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const override;
 868
 869 private:
 870     KItemListWidgetInformant *m_informant;
 871 };
 872
 873 template<class T>
 874 KItemListWidgetCreator<T>::KItemListWidgetCreator()
 875     : m_informant(T::createInformant())
 876 {
 877 }
 878
 879 template<class T>
 880 KItemListWidgetCreator<T>::~KItemListWidgetCreator()
 881 {
 882     delete m_informant;
 883 }
 884
 885 template<class T>
 886 KItemListWidget *KItemListWidgetCreator<T>::create(KItemListView *view)
 887 {
 888     KItemListWidget *widget = static_cast<KItemListWidget *>(popRecycleableWidget());
 889     if (!widget) {
 890         widget = new T(m_informant, view);
 891         addCreatedWidget(widget);
 892     }
 893     widget->setParentItem(view);
 894     return widget;
 895 }
 896
 897 template<class T>
 898 void KItemListWidgetCreator<T>::calculateItemSizeHints(QVector<std::pair<qreal, bool>> &logicalHeightHints,
 899                                                        qreal &logicalWidthHint,
 900                                                        const KItemListView *view) const
 901 {
 902     return m_informant->calculateItemSizeHints(logicalHeightHints, logicalWidthHint, view);
 903 }
 904
 905 template<class T>
 906 qreal KItemListWidgetCreator<T>::preferredRoleColumnWidth(const QByteArray &role, int index, const KItemListView *view) const
 907 {
 908     return m_informant->preferredRoleColumnWidth(role, index, view);
 909 }
 910
 911 /**
 912  * @brief Base class for creating KItemListGroupHeaders.
 913  *
 914  * It is recommended that applications simply use the KItemListGroupHeaderCreator-template class.
 915  * For a custom implementation the methods create() and recycle() must be reimplemented.
 916  * The intention of the group-header creator is to prevent repetitive and expensive instantiations and
 917  * deletions of KItemListGroupHeaders by recycling existing header instances.
 918  */
 919 class DOLPHIN_EXPORT KItemListGroupHeaderCreatorBase : public KItemListCreatorBase
 920 {
 921 public:
 922     ~KItemListGroupHeaderCreatorBase() override;
 923     virtual KItemListGroupHeader *create(KItemListView *view) = 0;
 924     virtual void recycle(KItemListGroupHeader *header);
 925 };
 926
 927 template<class T>
 928 class KItemListGroupHeaderCreator : public KItemListGroupHeaderCreatorBase
 929 {
 930 public:
 931     ~KItemListGroupHeaderCreator() override;
 932     KItemListGroupHeader *create(KItemListView *view) override;
 933 };
 934
 935 template<class T>
 936 KItemListGroupHeaderCreator<T>::~KItemListGroupHeaderCreator()
 937 {
 938 }
 939
 940 template<class T>
 941 KItemListGroupHeader *KItemListGroupHeaderCreator<T>::create(KItemListView *view)
 942 {
 943     KItemListGroupHeader *widget = static_cast<KItemListGroupHeader *>(popRecycleableWidget());
 944     if (!widget) {
 945         widget = new T(view);
 946         addCreatedWidget(widget);
 947     }
 948     return widget;
 949 }
 950
 951 #endif